® © 2009 Open Geospatial Consortium, Inc. Towards a common information model for water 71st OGC Technical Committee Mountain View, CA. USA Rob Atkinson Presented by Peter Fitch December 8, 2009 Sponsored and hosted by

OGC ® Scope Charter implies Who, Why –WMO auspices –Multiple stakeholders –Experiences around the table –Route to implementation What? –Core requirements Technical –How? Practical –Who –When

OGC ® What is the role of a common information model? INSPIRE Model WMO Metadata Profile WMOId:definition InspireId:definition lineage geometry Rhine Common concept, need to link or share data across domains

OGC ® Design INSPIRE Model 1 WMO Metadata Profile InspireId:ref lineage geometry Domain Model Id:definition WMO_Id:ref INSPIRE Model 2 relatedFeature:ref Model 2 not dependent on detail of model 1

OGC ® Identifiers Identifiers are not trivial… Architectural specification – e.g WFS 1.0 doesn’t allow gml:name to be queried using qualifier (oops!) –relationship of identifiers to a common model –Global scope of identifiers or ability to declare relationships? Implementation choices…

OGC ® INSPIRE base types

OGC ® An example No direct link to base types in model

OGC ® Rhine a abfg UUID Rhine GRDC …

OGC ® Multiple patterns

OGC ® Possible solution Model identity explicitly in a conceptual (semantic) framework and always explicitly map implementation models back to this. C.f. the “identity carrier pattern” Atkinson et al, IJSDI vol2 Can be retrofitted to INSPIRE suit of specs (and solutions) “idiom” to be refined, but mapping is external to both source and target (like RDF model), and can be retrofitted.

OGC ® An architectural option.. Separate common domain model from implementation profiles –Allow multiple implementations to be mapped to common semantics –Common semantics can be used to support identifier mapping –“model-mapping” is part of any overall system model –Mappings do not need to “pollute” either implementation or conceptual model –Mappings become “evidence of implementation” of domain model, using existing systems –Decouples governance cycle of key aspects –Versioning key to keep multiple mappings up to date,

OGC ® Testing It is possible to test a common domain model by mapping available implementations to it. Are there Use Cases out there not supported by current implementations? Who is willing to provide a minimal set of real data as test cases for the model? –Need someone willing to create mapping to common model –CSIRO can assist with some tools –HUMBOLDT project may provide mapping tools too –(CSIRO to at least interoperate with HUMBOLDT mappings)

OGC ® Towards a common domain model.. Scope – identifiers of real world objects independent of implementation profiles –WMO definition consistent –Link between WaterML and Hydrology Feature Types –Informative mappings to key implementations Next step: decisions –UML as normative – is there a realistic alternative? –Which version – ISO HMWG compatible, not INSPIRE idiom? –Where (Registry Owner – SDSC alongside WaterML) –Who (WMO is Register Owner, who is Register Control Body?) –CSIRO can play role as model editors (Register Manager)